Pixel 1 - note the fishman's feet are right on the flames

Pixel 2 - note there is a single pixel between the bottom of his feet and the top of the flames

If you have done that correctly when you activate the watch there will not be a bat in front of you. Jump over the pit and jump up the platforms. As you jump to the highest platform walk to about the midpoint of the platform and activate the watch as the bat swoops down and the fishman pops up. You will whip the fishman and the candle, collect the holy water and be able to walk and jump out over the bat to damage boost into the rock platforms that normally only the fishmen are able to access.